i got a 2007 honda civic lx and honeslty my mpg sucks alot. The best tank iv gotten was like 22 and in the last few months of cold weather iv been getting roughly 165 miles to 190 miles in that range per tank so with an 11 gallon tank this gas mileage is terrible. i never floor the thing at all and i usually keep it under 4k rpm i use sunoco gas 87 the cheapest grade of gas. what u guys think about this

its a mixture of town and highway driving, but even around town i still drive around 50-60

 

my buddy had same on his was power sensor switch in tranny.
he could feel clunck every now and again

 

I'm having the same problem. Would the power sensor thing you talk about also happen if its a manual transmission?

 

Somethings wrong cause my 2009 LX sedan gets around 30 city & 41 highway.

 

I have kind of the same problem in my 07 si. I added a cold air intake hoping it would help a little with airflow, but my mpg is around 27 highway... I know that it's a 2.0, but I thought I'd be getting better mpgs if I baby it and do mostly expressway.

Would a chip help in my situation? Or retuning the computer? Perhaps a jet chip?

 

Check to see if the exhaust manifold is cracked. Of course my civic is old but the a small 1 inch hairline crack decreased mpg by 5 b/c it caused the 02 sensor to read bad.

 

well with out going over it with a fine tooth comb, i haven't seen any cracks of any type in it...

i also wish i knew why it sometimes sputtered first thing in the morning. i've never known a car to seem hestitant when applying when it's cold.